[clang] [clang-tools-extra] Reland [clang][Sema, Lex, Parse] Preprocessor embed in C and C++ (PR #95802)

[Mariya Podchishchaeva via cfe-commits]

Fznamznon wrote:

This fixes https://github.com/llvm/llvm-project/pull/68620#issuecomment-2163448739 .
There was also https://github.com/llvm/llvm-project/pull/68620#issuecomment-2163603239 reported, but I'm not able to access proper logs. The link points to sanitizer buildbots so I suppose it might be the same memory leak.
With this patch and sanitizer build only `Clang-Unit :: Lex/./LexTests/67/120` fails, which also fails on main.

https://github.com/llvm/llvm-project/pull/95802